In the 1990s, researchers began to investigate the leadership traits associated with “social intelligence,” characterized as those abilities to understand one’s own and others’ feelings, behaviors, and thoughts and to act appropriately (Marlowe, 1986). Zaccaro (2002) defined social intelligence as having such capacities as social awareness, social acumen, self-monitoring, and the ability to select and enact the best response given the contingencies of the situation and social environment. A number of empirical studies showed these capacities to be a key trait for effective leaders. Zaccaro, Kemp, and Bader (2004) included such social abilities in the categories of leadership traits they outlined as important leadership attributes (see Table 2.1).
Table 2.1 provides a summary of the traits and characteristics that were identified by researchers from the trait approach. It illustrates clearly the breadth of traits related to leadership. Table 2.1 also shows how difficult it is to select certain traits as definitive leadership traits; some of the traits appear in several of the survey studies, whereas others appear in only one or two studies. Regardless of the lack of precision in Table 2.1, however, it represents a general convergence of research regarding which traits are leadership traits.
What, then, can be said about trait research? What has a century of research on the trait approach given us that is useful? The answer is an extended list of traits that individuals might hope to possess or wish to cultivate if they want to be perceived by others as leaders. Some of the traits that are central to this list include intelligence, self-confidence, determination, integrity, and sociability (Table 2.2).
Intelligence or intellectual ability is positively related to leadership. Based on their analysis of a series of recent studies on intelligence and various indices of leadership, Zaccaro et al. (2004) found support for the finding that leaders tend to have higher intelligence than nonleaders. Having strong verbal ability, perceptual ability, and reasoning appears to make one a better leader. Although it is good to be bright, the research also indicates that a leader’s intellectual ability should not differ too much from that of the subordinates. If the leader’s IQ is very different from that of the followers, it can have a counterproductive impact on leadership. Leaders with higher abilities may have difficulty communicating with followers because they are preoccupied or because their ideas are too advanced for their followers to accept.